000
FXUS63 KUNR 081718
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1018 AM MST Thu Dec 8 2016
.UPDATE...
Issued at 1018 AM MST Thu Dec 8 2016
Temps continue to slowly warm this morning...but a chilly day
still expected. Wind chills have risen above advisory
criteria so have cancelled the advisory. With relatively light
winds expected today across most of the CWA...wind chills of zero
to 10 below are expected during the daytime hours.
&&
.SHORT TERM...(Today Through Friday Night)
Issued at 241 AM MST Thu Dec 8 2016
Current surface analysis shows strong low pressure now over
Quebec, with 1045 mb surface high over southern Alberta. Pressure
gradient between the two systems is continuing to produce breezy
to windy conditions across the eastern Dakotas and Minnesota.
Large upper level trof covers much of Canada and the United
States, with strong jet stretching from the Southern Plains to the
northeast US. Skies are mostly clear across the area. Temperatures
at 3am range from around zero to 15 below.
Frigid weather will continue through the short term period, with
temps 15 to 30 degrees below average through Friday night. Arctic
high will slowly move southeast into the Northern Plains today,
with winds finally diminishing across the area. This will allow
for bitter cold temps to continue. High temperatures today will be
similar to yesterday, in the single digits to teens. Temperatures
tonight will once again fall below zero across much of the area.
With the lighter winds tonight, wind chill values should drop no
lower than 10 below to 20 below zero.
Cloud cover will be on the increase on Friday, as warmer air
begins to move in aloft, and a weak impulse lifts through the
Northern Plains. Small chances for light snow will be possible
across the SD plains. Temperatures will remain well below average,
but some warming will occur across parts of Northeast Wyoming and
the Black Hills, where highs will rise into the teens.
Temperatures across the SD plains north and east of the Black
Hills will remain in the single digits. Temperatures will continue
to moderate a bit into Friday night, with only northwestern SD
falling below zero for low temps. Strong warm air advection aloft
will being additional chances for light snow across the entire
area late Friday night.
.LONG TERM...(Saturday Through Wednesday)
Issued at 241 AM MST Thu Dec 8 2016
The chances of light snow will continue from Saturday into Sunday
as relatively warmer air aloft overruns the colder air at the
surface. Any snow accumulations will be light, generally around an
inch or less with around 2 inches possible over parts of
northwestern and central South Dakota. Colder air will push back
into the region Saturday night/Sunday. Much colder than average
temperatures will remain across the region through the rest of the
long term forecast with chances of light snow again Monday/Monday
night then again toward the end of the week.
&&
.AVIATION...(For the 18Z TAFS Through 18Z Friday)
Issued At 1018 AM MST Thu Dec 8 2016
VFR conditions are expected through the forecast period.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
Update...13
SHORT TERM...15
LONG TERM...10
AVIATION...7